DESCRIPTION: (Applicant's Description) The long term goals of Core A, Molecular and Cellular Assays, are [1] to provide genotypic and phenotypic characterization of WRN wild-type, heterozygous, and null human- and mouse-derived cells, cell lines, or tissues generated by this program, and [2] to procure and bank sarcomas and meningiomas for the Program Project in order to perform WRN sequence analysis. These goals will be achieved by the following specific aims: 1. In human cell lines in which WRN expression has been manipulated by allele transfer; in cells and cell lines derived from tissues of knock out mice; and in yeast the Core will provide: a. analysis of genomic instability by cytogenetic examination for gross chromosomal rearrangements characteristic of Werner's syndrome, including whole chromosome loss or gain and variegated translocation mosaicism. b. assessment of WRN expression at the RNA level. c. DNA sequence analysis for verification of WRN gene mutations. 2. For sarcomas and meningiomas obtained from surgical resections, the Core will collect and bank tissue for histologic characterization and DNA and RNA isolation for use in the Program Project and perform WRN DNA sequence analysis of paired normal and tumor samples.